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Paper: ORFEUS Observations of Cool Stars: Electron Density Measurements
Volume: 154, Cool Stars, Stellar Systems and the Sun: Tenth Cambridge Workshop
Page: 1022
Authors: Dupree, A. K.; Brickhouse, N. S.; Hurwitz, M.
Abstract: The Berkeley Spectrograph on ORFEUS-1 and ORFEUS-2 obtained far ultraviolet spectra of many cool stars. The density diagnostic of C 3 (lambda1176/lambda977), used to evaluate the density at the base of the transition region (T ~70000K), demonstrates that a range of electron densities are present, ranging from <= 10^8 to > 10^{10.5} cm^{-3} in single and binary systems. The hybrid stars appear to have lower transition region densities than the active systems. Comparison with the larger electron density values derived from EUVE spectra representative of T ~10^7 K suggests the existence of several coronal atmospheric components.
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